Technical Field
The present invention relates to an epoxy compound having an alkoxysilyl group (hereinafter ‘alkoxysilylated epoxy compound’), a composite thereof exhibiting good heat resistance properties and/or a cured product thereof exhibiting good flame retardancy, a method for preparing the same, a composition comprising the same, a cured product thereof, and a use thereof. More particularly, the present invention relates to an alkoxysilylated epoxy compound, composites thereof exhibiting good heat resistance properties, in particular, low coefficients of thermal expansion (CTE) and high glass transition temperatures (including transition temperature-less (Tg-less) states, which means that the composites do not have a glass transition temperature) and not requiring a separate coupling agent, a method for preparing the same, a composition comprising the same, a cured product thereof, and a use thereof.
Background Art
The coefficient of thermal expansion of a cured epoxy product is significantly high, on the level of several to several tens of times than the CTE of a ceramic material or a metal material. Thus, in the case that an epoxy material is used in conjunction with an inorganic material or a metal material, the properties and processability of a part may be significantly degraded due to the different CTEs of the polymer material and the inorganic material or the metal material. For example, during semiconductor packaging in which a silicon wafer and an epoxy substrate are used in parallel, product defects such as the generation of cracks, the warpage in a substrate, the peeling of a coating layer, the cracking of a substrate, and the like, may be generated due to a high CTE-mismatch between constituent elements due to changes in processing and/or applied temperature conditions.
Because of the high CTE of the epoxy material and the resultant dimensional change of the material, the development of technologies such as next generation semiconductor substrates, printed circuit boards (PCBs), packaging, organic thin film transistors (OTFTs), and flexible display substrates may be limited. Particularly, at the current time, in the semiconductor and PCB fields, designers are facing challenges in the design of next generation parts requiring high degrees of integration, miniaturization, flexibility, performance, and the like, in securing processability and reliability in parts due to polymer materials having significantly high CTEs as compared to metal/ceramic materials. In other words, due to the high thermal expansion properties of polymer materials at part processing temperatures, defects may be generated therein, processability may be limited, and the design of parts and the securing of processability and reliability therein may be objects of concern. Accordingly, improved thermal expansion properties, namely dimensional stability of the epoxy material are necessary in order to secure processability and reliability in electronic parts.
To date, in order to obtain a low CTE in a cured epoxy product, (1) a method of producing a composite of an epoxy compound with inorganic particles (an inorganic filler) and/or fabrics or (2) a method of designing a novel epoxy compound having a decreased CTE have been used.
In the case that the composite of the epoxy compound and the inorganic particles as the filler is formed in order to improve thermal expansion properties, a large amount of inorganic silica particles, having a diameter of about 2 to 30 μm, is required to be used to obtain a CTE decrease effect. However, due to the presence of the large amount of inorganic particles, the processability and physical properties of the parts may be deteriorated. That is, the presence of the large amount of inorganic particles may decrease fluidity, and voids may be generated during the filling of narrow spaces. In addition, the viscosity of the material may increase exponentially due to the addition of the inorganic particles. Further, the size of the inorganic particles tends to decrease due to semiconductor structure miniaturization. In the case that a filler having a particle size of 1 μm or less is used, an increase in viscosity may be intensified. In the case that inorganic particles having a large average particle diameter are used, the frequency of insufficient filling in the case of a composition comprising a resin and the inorganic particles may increase. While the CTE may largely decrease in the case that a composition comprising an organic resin and a fiber as the filler is used, the CTE may remain high, as compared to that of a silicon chip or the like.
As described above, the manufacturing of highly integrated and high performance electronic parts for next generation semiconductor substrates, PCBs, and the like, may be limited due to limitations in the technology of forming composites of epoxy resins. Thus, the development of an epoxy composite having improved brittleness and adhesiveness as well as improved heat resistance properties—namely, a low CTE and a high glass transition temperature—is required to overcome poor thermal properties due to a high CTE and processability of a common epoxy composite.